U.S. patent number 10,891,011 [Application Number 16/568,829] was granted by the patent office on 2021-01-12 for touch sensor having sensing electrodes and optical compensation patterns and image display device including the same.
This patent grant is currently assigned to DONGWOO FINE-CHEM CO., LTD.. The grantee listed for this patent is DONGWOO FINE-CHEM CO., LTD.. Invention is credited to Do Hyoung Kwon, Jun Gu Lee, Sung Jin Noh, Sang Jin Park, Han Tae Ryu.
United States Patent |
10,891,011 |
Park , et al. |
January 12, 2021 |
Touch sensor having sensing electrodes and optical compensation
patterns and image display device including the same
Abstract
A touch sensor includes a substrate layer, sensing electrodes on
the substrate layer, and optical compensation patterns. The sensing
electrodes include electrode lines therein which extend in
different directions to cross each other. The sensing electrodes
are defined by separation regions at which portions of the
electrode lines are cut. The optical compensation patterns are
disposed at a different level or a different plane from that of the
sensing electrodes. The optical compensation pattern at least
partially fills the separation regions in a planar view. Optical
properties of the touch sensor are improved by the optical
compensation pattern, and visibility of electrodes is
prevented.
Inventors: |
Park; Sang Jin (Gyeonggi-do,
KR), Kwon; Do Hyoung (Gyeonggi-do, KR),
Noh; Sung Jin (Gyeonggi-do, KR), Ryu; Han Tae
(Chungcheongbuk-do, KR), Lee; Jun Gu (Gyeonggi-do,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
DONGWOO FINE-CHEM CO., LTD. |
Jeollabuk-do |
N/A |
KR |
|
|
Assignee: |
DONGWOO FINE-CHEM CO., LTD.
(Jeollabuk-Do, KR)
|
Family
ID: |
1000005296282 |
Appl.
No.: |
16/568,829 |
Filed: |
September 12, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200089372 A1 |
Mar 19, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Sep 18, 2018 [KR] |
|
|
10-2018-0111483 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/0446 (20190501); G06F 2203/04112 (20130101); G06F
2203/04111 (20130101) |
Current International
Class: |
G06F
3/044 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
10-2014-0092366 |
|
Jul 2014 |
|
KR |
|
Primary Examiner: Yang; Kwang-Su
Attorney, Agent or Firm: The PL Law Group, PLLC
Claims
What is claimed is:
1. A touch sensor, comprising: a substrate layer; sensing
electrodes on the substrate layer, the sensing electrodes
comprising first electrode lines in a first direction and second
electrode lines crossing the first electrode lines and extending in
a second direction different from the first direction; separation
regions formed by cutting portions of the first and second
electrode lines to electrically insulate or separate the first
sensing electrode lines and the second sensing electrode lines from
each other; and optical compensation patterns disposed at a
different level or a different plane from that of the sensing
electrodes, the optical compensation patterns at least partially
filling the separation regions in a planar view, wherein the
sensing electrodes comprises: first sensing electrodes arranged
along the first direction parallel to a top surface of the
substrate layer; second sensing electrodes arranged along the
second direction parallel to the top surface of the substrate layer
and perpendicular to the first direction; a bridge electrode
electrically connecting the first sensing electrodes neighboring in
the first direction to each other; and a connecting portion
integrally connected to the second sensing electrodes neighboring
in the second direction at the same level as that of the second
sensing electrodes, wherein the first sensing electrodes and the
second sensing electrodes are disposed at the same level or at the
same plane to be separated from each other by the separation
regions; and the bridge electrode is disposed over the connecting
portion or under the connecting portion to cross the connecting
portion, and the bridge electrode and the optical compensation
patterns are disposed at the same level or at the same plane.
2. The touch sensor according to claim 1, wherein the optical
compensation pattern entirely fills the separation regions in the
planar view.
3. The touch sensor according to claim 2, wherein each of the
separation regions is filled with a whole of the optical
compensation pattern or a portion of the optical compensation
pattern in the planar view.
4. The touch sensor according to claim 2, wherein the sensing
electrodes have a mesh structure that includes a plurality of unit
cells each defined by neighboring first electrode lines and
neighboring second electrode lines.
5. The touch sensor according to claim 4, wherein the separation
regions are each defined as a region at which at least one vertex
or at least one side of a unit cell of the plurality of unit cell
is cut.
6. The touch sensor according to claim 5, wherein the optical
compensation pattern has a shape of a cross, a cut wavy line or a
bar-pattern.
7. The touch sensor according to claim 4, wherein each of the unit
cells includes a plurality of curved lines selected from a sine
curve, a cosine curve, a conic section, a catenary, a curve of
pursuit, a cycloid, a trochoid or a cardioid.
8. The touch sensor according to claim 4, wherein a boundary of
each of the unit cells includes a plurality of water waves which
have the same length corresponding to one period.
9. The touch sensor according to claim 8, wherein the boundary of
each of the unit cells consists of the water waves.
10. The touch sensor according to claim 1, further comprising an
insulation layer partially covering the first sensing electrodes,
wherein the bridge electrode is insulated from the second sensing
electrodes on the insulation layer to connect the neighboring first
sensing electrodes.
11. The touch sensor according to claim 1, further comprising an
insulation layer partially covering the bridge electrode, wherein
the first sensing electrodes and the second sensing electrodes are
disposed on the insulation layer, and the neighboring first sensing
electrodes are electrically connected via the bridge electrode
while being insulated from the second sensing electrodes.
12. An image display device, comprising: a display panel; and the
touch sensor of claim 1 on the display panel.
13. The image display device according to claim 12, further
comprising an adhesive layer combining the display panel and the
touch sensor with each other.
Description
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY
This application claims priority to Korean Patent Application No.
10-2018-0111483 filed on Sep. 18, 2018 in the Korean Intellectual
Property Office (KIPO), the entire disclosure of which is
incorporated by reference herein.
BACKGROUND
1. Field
The present invention relates to a touch sensor and an image
display device including the same. More particularly, the present
invention relates to a touch sensor including sensing electrode
patterns and an image display device including the same.
2. Description of the Related Art
As information technologies are being developed, various demands in
display devices having thinner dimension, light-weight, high
efficiency in power consumption, etc., are increasing. The display
device may include a flat panel display device such as a liquid
crystal display (LCD) device, a plasma display panel (PDP) device,
an electro-luminescent display device, an organic light emitting
diode (OLED) display device, etc.
A touch panel or a touch sensor capable of inputting a user's
direction by selecting an instruction displayed on a screen with a
finger or an inputting tool is also developed. The touch panel or
the touch sensor may be combined with the display device so that
display and information input functions may be implemented in one
electronic device.
As a resolution of the display device is increased to a quad-high
definition (QHD) level, an ultra-high definition (UHD) level, etc.,
a high resolution of the touch sensor may be also needed.
Accordingly, a critical dimension and a pitch of sensing electrodes
included in the touch sensor may be decreased.
The touch sensor may be stacked on a display panel, and an image
quality of the display device may be deteriorated when the sensing
electrodes of the touch sensor are viewed by a user. Further, a
moire phenomenon may be caused when the sensing electrode overlaps
electrodes or wirings of the display panel.
For example, as disclosed in Korean Patent Application Publication
No. 2014-0092366, various image display devices combined with a
touch screen panel including a touch sensor has been developed
recently. However, demands of a touch sensor or a touch panel
having improved compatibility with the image display device are
continuously increasing.
SUMMARY
According to an aspect of the present invention, there is provided
a touch sensor having improved optical property and electrical
reliability.
According to an aspect of the present invention, there is provided
a window stack structure and an image display device including the
touch sensor that has improved optical property and electrical
reliability
The above aspects of the present inventive concepts will be
achieved by the following features or constructions:
(1) A touch sensor, comprising: a substrate layer; sensing
electrodes on the substrate layer, the sensing electrodes including
electrode lines therein which extend in different directions to
cross each other, the sensing electrodes being defined by
separation regions at which portions of the electrode lines are
cut; and optical compensation patterns disposed at a different
level or a different plane from that of the sensing electrodes, the
optical compensation pattern at least partially filling the
separation regions in a planar view.
(2) The touch sensor according to the above (1), wherein the
optical compensation pattern entirely fills the separation region
in the planar view.
(3) The touch sensor according to the above (2), wherein the
separation region is filled with a whole of the optical
compensation pattern or a portion of the optical compensation
pattern in the planar view.
(4) The touch sensor according to the above (2), wherein the
sensing electrodes have a mesh structure that includes a plurality
of unit cells defined by the electrode lines neighboring each other
and extending in different directions to cross each other.
(5) The touch sensor according to the above (4), wherein the
separation region is defined as a region at which at least one
vertex or at least one side of the unit cell is cut.
(6) The touch sensor according to the above (5), wherein the
optical compensation pattern has a shape of a cross, a cut wavy
line or a bar-pattern.
(7) The touch sensor according to the above (4), wherein the unit
cell includes a plurality of curved lines selected from a sine
curve, a cosine curve, a conic section, a catenary, a curve of
pursuit, a cycloid, a trochoid or a cardioid.
(8) The touch sensor according to the above (4), wherein a boundary
of the unit cell includes a plurality of water waves which have the
same length corresponding to one period.
(9) The touch sensor according to the above (8), wherein the
boundary of the unit cell consists of the water waves.
(10) The touch sensor according to the above (1), wherein the
sensing electrodes includes: first sensing electrodes arranged
along a first direction parallel to a top surface of the substrate
layer; and second sensing electrodes arranged along a second
direction parallel to the top surface of the substrate layer, the
first direction and the second direction being perpendicular to
each other, wherein the first sensing electrode and the second
sensing electrode are separated from each other by the separation
regions.
(11) The touch sensor according to the above (10), further
comprising: a bridge electrode electrically connecting the first
sensing electrodes neighboring in the first direction to each
other; and a connecting portion by which the second sensing
electrodes neighboring in the second direction are connected to
each other.
(12) The touch sensor according to the above (11), wherein the
connecting portion is integrally connected to the second sensing
electrodes, and the bridge electrode is disposed over the
connecting portion or under the connecting portion to cross the
connecting portion.
(13) The touch sensor according to the above (12), wherein the
bridge electrode and the optical compensation pattern are disposed
at the same level or at the same plane.
(14) The touch sensor according to the above (13), further
comprising an insulation layer partially covering the sensing
electrodes, wherein the bridge electrode is insulated from the
second sensing electrodes on the insulation layer to connect the
neighboring first sensing electrodes.
(15) The touch sensor according to the above (13), further
comprising an insulation layer partially covering the bridge
electrode, wherein the sensing electrodes are disposed on the
insulation layer, and the neighboring first sensing electrodes are
electrically connected via the bridge electrode while being
insulated from the second sensing electrodes.
(16) An image display device, comprising: a display panel; and the
touch sensor according to any one of the above (1) to (15) on the
display panel.
(17) The image display device according to the above (16), further
comprising an adhesive layer combining the display panel and the
touch sensor with each other.
In a touch sensor according to exemplary embodiments as described
above, a sensing electrode may include a plurality of electrode
lines, and an optical compensation pattern superimposed over a
separation region or a cut area of the electrode lines at an upper
level of the sensing electrode. The optical compensation pattern
may fill the separation region from a direction of a viewer, and
thus a visibility of electrodes due to an electrode arrangement
deviation may be reduced or avoided. Further, the optical
compensation pattern may be formed at the upper level or a lower
level of the sensing electrode, and thus may be formed without a
patterning limitation of the sensing electrode and a dimension of
the optical compensation pattern may be decreased.
The sensing electrode may include unit cells defined by the
electrode lines, and sides of a boundary of the unit cell may have
the same water wave form. The unit cells may be regularly repeated
so that the visibility of electrodes and a moire phenomenon may be
effectively reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are a top planar view and a cross-sectional view,
respectively, illustrating a schematic construction of a touch
sensor in accordance with exemplary embodiments;
FIG. 3 is a cross-sectional view illustrating a schematic
construction of a touch sensor in accordance with some exemplary
embodiments;
FIGS. 4 to 6 are schematic top planar views illustrating a pattern
structure of sensing electrodes in accordance with exemplary
embodiments;
FIGS. 7 to 9 are schematic top planar views illustrating a pattern
structure of sensing electrodes in accordance with some exemplary
embodiments;
FIGS. 10 to 14 are schematic top planar views illustrating shapes
of mesh structures and unit cells included in sensing electrodes in
accordance with exemplary embodiments; and
FIG. 15 is a schematic cross-sectional view illustrating a window
stack structure and an image display device in accordance with
exemplary embodiments.
DETAILED DESCRIPTION
According to exemplary embodiments of the present invention, there
is provided a touch sensor which includes sensing electrodes
including a plurality of electrode lines therein, and an optical
compensation pattern disposed at an upper level or a lower level of
the sensing electrodes so that visibility of electrodes may be
reduced or suppressed. Further, an image display device including
the touch sensor is provided.
Hereinafter, the present invention will be described in detail with
reference to the accompanying drawings. However, those skilled in
the art will appreciate that such embodiments described with
reference to the accompanying drawings are provided to further
understand the spirit of the present invention and do not limit
subject matters to be protected as disclosed in the detailed
description and appended claims.
In the accompanying figures, two directions parallel to a top
surface of a touch sensor or a substrate layer 105 and crossing
each other may be designated as a first direction and a second
direction. For example, the first direction and the second
direction are perpendicular to each other.
FIGS. 1 and 2 are a top planar view and a cross-sectional view,
respectively, illustrating a schematic construction of a touch
sensor in accordance with exemplary embodiments. For example, FIG.
2 is a cross-sectional view at an intersection region C designated
in FIG. 1. FIG. 2 illustrates an example of a touch sensor having a
top-bridge construction.
Referring to FIGS. 1 and 2, a touch sensor 100 may include the
substrate layer 105 and sensing electrodes 110 and 130 arranged on
the substrate layer 105.
The substrate layer 105 may include a film-type substrate serving
as a base layer for forming the sensing electrodes 110 and 130, or
an object on which the sensing electrodes 110 and 130 are formed.
In some embodiments, the substrate layer 105 may be a display panel
on which the sensing electrodes 110 and 130 may be directly
formed.
For example, the substrate layer 105 may include a substrate or a
film material commonly used in a touch sensor. For example, the
substrate layer 105 may include glass, polymer and/or an inorganic
insulation material. The polymer may include, e.g., cyclo olefin
polymer (COP), polyethylene terephthalate (PET), polyacrylate
(PAR), polyether imide (PEI), polyethylene naphthalate (PEN),
polyphenylene sulfide (PPS), polyallylate, polyimide (PI),
cellulose acetate propionate (CAP), polyether sulfone (PES),
cellulose triacetate (TAC), polycarbonate (PC), cyclo olefin
copolymer (COC), polymethylmethacrylate (PMMA), etc. The inorganic
insulation material may include, e.g., silicon oxide, silicon
nitride, silicon oxynitride, a metal oxide, etc.
A layer or a film member in an image display device to which the
touch sensor is applied may also serve as the substrate layer 105.
For example, an encapsulation layer or a passivation layer included
in the display panel may serve as the substrate layer 105.
The sensing electrodes 110 and 130 may include first sensing
electrodes 110 and second sensing electrodes 130. For example, the
sensing electrodes 110 and 130 may be arranged to be operated by a
mutual capacitance type.
The first sensing electrodes 110 may be arranged along the first
direction. Each first sensing electrode 110 may have an island
pattern shape, and the first sensing electrodes 110 neighboring in
the first direction may be electrically connected to each other by
a bridge electrode 115.
Accordingly, a first sensing electrode row extending in the first
direction may be defined, and a plurality of the first sensing
electrode rows may be arranged along the second direction.
The second sensing electrodes 130 may be arranged along the second
direction. The second sensing electrodes 130 neighboring in the
second direction may be connected to each other by a connecting
portion 135. The second sensing electrodes 130 and the connecting
portion 135 may be integrally connected to each other to be a
substantially unitary member. In this case, the second sensing
electrodes 130 and the connecting portion 135 may be formed by
patterning the same conductive layer to be placed at the same layer
or at the same level.
Accordingly, a second sensing electrode column extending in the
second direction may be defined, and a plurality of the second
sensing electrode columns may be arranged along the first
direction.
The sensing electrodes 110 and 130 and/or the bridge electrode 115
may include a metal, a metal alloy, a metal wire or a transparent
conductive oxide.
For example, the sensing electrodes 110 and 130 and/or the bridge
electrode 115 may include silver (Ag), gold (Au), copper (Cu),
aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr),
titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium
(V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc
(Zn), or an alloy thereof (e.g., silver-palladium-copper (APC)).
These may be used alone or in a combination thereof.
The sensing electrodes 110 and 130 and/or the bridge electrode 115
may include the transparent conductive oxide such as indium tin
oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc
tin oxide (IZTO), cadmium tin oxide (CTO), etc.
In some embodiments, the sensing electrodes 110 and 130 and/or the
bridge electrode 115 may include a multi-layered structure
including the transparent conductive oxide and the metal. For
example, the sensing electrodes 110 and 130 and/or the bridge
electrode 115 may have a triple-layered structure of a transparent
conductive oxide layer--a metal layer--a transparent conductive
oxide layer. In this case, a flexible property may be enhanced by
the metal layer so that a resistance may be reduced and a signal
transfer speed may be improved. Further, a resistance to corrosion
and a transparency may be enhanced by the transparent conductive
oxide layer.
As illustrated in FIG. 1, in some embodiments, boundaries of the
sensing electrodes 110 and 130 may have a substantially wavy
shape.
As illustrated in FIG. 2, an insulation layer 120 at least
partially covering the first sensing electrodes 110 and the
connecting portion 135 may be formed on the substrate layer 105.
The bridge electrode 115 may be disposed on the insulation layer
120 such that the neighboring first sensing electrodes 110 may be
electrically connected to each other via, e.g., contact holes
formed in the insulation layer 120.
A passivation layer 150 for protecting the touch sensor may be
formed on the insulation layer 120 and the bridge electrode
115.
The insulation layer 120 and/or the passivation layer 150 may
include an inorganic insulation material such as silicon oxide,
silicon nitride, etc., or an organic insulation material such as an
acryl-based resin, a siloxane-based resin, etc.
FIG. 3 is a cross-sectional view illustrating a schematic
construction of a touch sensor in accordance with some exemplary
embodiments. For example, a touch sensor having a bottom-bridge
construction is illustrated in FIG. 3. Detailed descriptions on
elements and structures substantially the same as or similar to
those illustrated in FIGS. 1 and 2 are omitted herein.
Referring to FIG. 3, the bridge electrode 115 may be disposed under
the sensing electrodes 110 and 130. For example, the bridge
electrode 115 may be formed on the substrate layer 105, and the
insulation layer 120 may be formed on the substrate layer 105 to
partially cover the bridge electrode 115. The insulation layer 120
may include a contact hole through which a top surface of the
bridge electrode 115 may be partially exposed.
The second sensing electrodes 130 may be arranged along the second
direction on the insulation layer 120 to be separated from the
bridge electrode 115.
The first sensing electrodes 110 may be formed on the insulation
layer to fill the contact holes and to be in contact with or
electrically connected to the bridge electrode 115. Accordingly,
the first sensing electrodes 110 neighboring in the first direction
may be electrically connected via the bridge electrode 115 while
being insulated from the second sensing electrodes 130.
FIGS. 4 to 6 are schematic top planar views illustrating a pattern
structure of sensing electrodes in accordance with exemplary
embodiments. Specifically, FIG. 4 illustrates a pattern structure
of the sensing electrodes 110 and 130 at the intersection region C
designated in FIG. 1. FIG. 5 selectively illustrates the bridge
electrode 115 and an optical compensation pattern 140 disposed at a
different layer or a different level from that of the sensing
electrodes 110 and 130. FIG. 6 illustrates a combination of FIGS. 4
and 5 in the same planar view.
Referring to FIG. 4, a pair of the first sensing electrodes 110 and
a pair of the second sensing electrodes 130 may be disposed at the
intersection region C of FIG. 1, and the pair of the second sensing
electrodes 130 may be integrally connected with the connecting
portion 135. The pair of the first sensing electrodes 110 may be
spaced apart from each other in the first direction with respect to
the connecting portion 135.
As illustrated in FIG. 4, the first sensing electrode 110 and the
second sensing electrode 130 may each include a mesh structure
defined by electrode lines crossing each other along the first and
second directions. For example, the electrode lines may include
first electrode lines extending in the first direction and second
electrode lines extending in the second direction.
For example, two neighboring second electrode lines extending in
the second direction and two neighboring first electrode lines
extending in the first direction may cross each other to define a
unit cell. A plurality of the unit cells may be repeatedly arranged
to define the mesh structure.
A shape of the mesh structure will be described in more detail with
reference to FIGS. 10 to 14 below.
A conductive layer having the mesh structure shape may be formed,
and then separation regions S may be formed so that the first
sensing electrode 110 and the second sensing electrode 130 may be
electrically insulated or separated from each other.
In exemplary embodiments, intersecting points of the electrode
lines or portions around vertices of the unit cells may be cut to
form the separation regions S. For example, the separation regions
S may be repeated along diagonal directions relative to the first
direction and the second direction so that the first sensing
electrode 110 and the second sensing electrode 130 may be divided
to form boundaries.
As illustrated in FIG. 4, the separation regions of the electrode
lines may be omitted at an area where two neighboring second
sensing electrodes 130 are adjacent to each other, and the
connecting portion 135 may be defined by at least one electrode
line that may not be cut and may extend in the second
direction.
Referring to FIG. 5, for example, the bridge electrode 115 may
include at least one cut pattern from an electrode line having
substantially the same shape as that of the electrode lines
extending in the first direction as illustrated in FIG. 4. In an
embodiment, the bridge electrode 115 may include at least two cut
patterns.
In exemplary embodiments, the optical compensation pattern 140 may
be disposed at an upper level or a lower level of the sensing
electrodes 110 and 130. As illustrated in FIG. 5, the optical
compensation pattern 140 may be disposed at the same level or the
same plane as that of the bridge electrode 115.
In an embodiment, as illustrated in FIG. 2, the bridge electrode
115 may be disposed on the insulation layer 120, and the optical
compensation pattern 140 may be disposed on the insulation layer
120 together with the insulation layer 120. In an embodiment, as
illustrated in FIG. 3, the bridge electrode 115 may be disposed on
the substrate layer 105, and the optical compensation pattern 140
may be disposed on the substrate layer 105 together with the bridge
electrode 115. In this case, the sensing electrodes 110 and 130 may
be disposed on the insulation layer 120 and may be disposed over
the optical compensation pattern 140 and the bridge electrode
115.
The optical compensation pattern 140 may have a shape substantially
the same as that of a cut portion of the electrode lines at the
separation region S. In an embodiment, the optical compensation
pattern 140 may have a substantially cross-shape as illustrated in
FIG. 5.
Referring to FIG. 6, the optical compensation pattern 140 may be
superimposed over the separation region S in a planar view as
designated by a dotted circle. The bridge electrode 115 may be
disposed over the connecting portion 135 or under the connecting
portion 135 to cross the connecting portion 135 in the planar
view.
A vacancy at the separation region S may be at least partially
filled or covered with the optical compensation pattern 140 in the
planar view. In exemplary embodiments, the separation region S may
be substantially fully filled with the optical compensation pattern
140 in the planar view.
In an embodiment, the optical compensation pattern 140 may have a
size substantially the same as that of the separation region S. In
this case, the separation region S may be substantially fully
filled with a whole of the optical compensation pattern 140 in the
planar view.
In an embodiment, the optical compensation pattern 140 may have a
size greater than that of the separation region S. In this case,
the separation region S may be substantially fully filled with a
partial portion of the optical compensation pattern 140 in the
planar view.
As illustrated in FIG. 6, the separation regions S may be filled
with the optical compensation patterns 140 in the planar view so
that the electrode lines included in the sensing electrodes 110 and
130 may be viewed as a continuous and seamless shape when the touch
sensor is observed in the planar view, and thus the separation
regions S may not be specified or divided.
Therefore, changes of a reflectivity, a refractive index, a color
sense, a pattern shape, etc., at the separation region S may be
prevented or reduced so that an electrode visibility at the
separation region S may be also prevented or reduced.
The optical compensation pattern 140 may be individually formed at
a different level or a different plane from that of the sensing
electrodes 110 and 130. Thus, a dimension or an area of the
separation region S may be decreased, and the electrode visibility
may be prevented more effectively.
FIGS. 7 to 9 are schematic top planar views illustrating a pattern
structure of sensing electrodes in accordance with some exemplary
embodiments.
Referring to FIG. 7, at least one side of the unit cell included in
the mesh structure may be cut to form the separation region S. For
example, portions of the electrode lines that may meet two diagonal
lines relative to the first direction and the second direction may
be cut to define the separation regions S.
In an embodiment, one first electrode line and one second electrode
line included in the unit cell which may meet the diagonal line may
be cut to form the separation regions S.
Referring to FIG. 8, an optical compensation pattern 145 that may
have a shape substantially the same as that of a portion cut from
the separation region S may be formed. In an embodiment, the
optical compensation pattern 145 may have a cut wavy line or a bar
pattern shape. As described above, the optical compensation
patterns 145 may be arranged on the same layer or the same plane as
that of the bridge electrode 115.
Referring to FIG. 9, the separation region S may be substantially
filled with the optical compensation pattern 145 (designated by a
dotted circle) from a planar view. The bridge electrode 115 may be
disposed over the connecting portion 135 or under the connecting
portion 135 to cross the connecting portion 135 in the planar
view.
As described above, the vacancies at the separation regions S may
be substantially completely filled or covered by the optical
compensation patterns 145 from the planar view. Thus, an electrode
pattern structure of the touch sensor may include a substantially
seamless mesh structure without cut portions when observed from the
planar view.
FIGS. 10 to 14 are schematic top planar views illustrating shapes
of mesh structures and unit cells included in sensing electrodes in
accordance with exemplary embodiments.
Referring to FIG. 10, the sensing electrode may include the mesh
structure as described with reference to FIG. 4. A unit cell 50
included in the mesh structure may include a plurality of curved
lines. For example, the curved line may include a sine curve, a
cosine curve, a conic section, a catenary, a curve of pursuit, a
cycloid, a trochoid, a cardioid, etc.
In some embodiments, the unit cell 50 may have a shape modified
from an imaginary rectangle designated by dotted lines, a side of
which is transformed into a water wave corresponding to one
period.
In an embodiment, the unit cell 50 may consist of the water waves
of the same waveform, and the unit cells 50 may be repeated to form
the mesh structure.
As described above, the mesh structure may be defined by the water
waves having the same waveform so that a spatial frequency
generated from the electrode lines may be normalized or equalized.
Thus, electrode visibility due to a spatial frequency deviation
generated when cells or electrode lines having different shapes are
included may be efficiently prevented.
Further, the mesh structure of the touch sensor may be defined by
the water waves so that a moire phenomenon caused by regular
overlap of the touch sensor with wirings and electrodes included in
a display panel may be effectively reduced or avoided.
Referring to FIG. 11, the unit cells 50 of FIG. 10 may be repeated
in a zigzag arrangement to form the mesh structure of the sensing
electrode. Accordingly, the moire phenomenon by the overlap with
the display panel may be additionally reduced by a staggered
arrangement of the unit cells 50.
Referring to FIG. 12, a unit cell 52 may have a shape modified from
an imaginary rhombus designated by dotted lines, a side of which is
transformed into a water wave corresponding to one period, and the
unit cell 52 may include four water waves having the same
waveform.
Referring to FIG. 13, a unit cell 54 may have a shape modified from
an imaginary hexagon designated by dotted lines, a side of which is
transformed into a water wave corresponding to one period, and the
unit cell 54 may include six water waves having the same
waveform.
Referring to FIG. 14, a unit cell 56 may include a pair of water
waves symmetrical to each other in an imaginary hexagon designated
by dotted lines. Each water wave may have a length corresponding to
one period.
According to exemplary embodiments of the present invention, an
image display device including the touch sensor or the touch screen
panel as described above is provided.
FIG. 15 is a schematic cross-sectional view illustrating a window
stack structure and an image display device in accordance with
exemplary embodiments.
A window stack structure 250 may include a window substrate 230, a
polarizing layer 210 and a touch sensor 200 according to exemplary
embodiments as described above.
The window substrate 230 may include, e.g., a hard coating film. In
an embodiment, a light-shielding pattern 235 may be formed on a
peripheral portion of a surface of the window substrate 230. The
light-shielding pattern 235 may include a color-printed pattern,
and may have a single-layered or multi-layered structure. A bezel
portion or a non-display region of the image display device may be
defined by the light-shielding pattern 235.
The polarizing layer 210 may include a coating-type polarizer or a
polarizing plate. The coating-type polarizer may include a liquid
crystal coating layer that may include a cross-linkable liquid
crystal compound and a dichroic dye. In this case, the polarizing
layer 210 may include an alignment layer for providing an
orientation of the liquid crystal coating layer.
For example, the polarizing plate may include a polyvinyl
alcohol-based polarizer and a protective film attached to at least
one surface of the polyvinyl alcohol-based polarizer.
The polarizing layer 210 may be directly attached to the surface of
the window substrate 230 or may be attached via a first adhesive
layer 220.
The touch sensor 200 may be included in the window stack structure
250 as a film or a panel. In an embodiment, the touch sensor 200
may be combined with the polarizing layer 210 via a second adhesive
layer 225.
As illustrated in FIG. 15, the window substrate 230, the polarizing
layer 210 and the touch sensor 200 may be sequentially positioned
from a viewer's side. In this case, sensing electrodes of the touch
sensor 200 may be disposed under the polarizing layer 210 so that
electrode patterns may be effectively prevented from being seen by
the viewer.
If the touch sensor 200 includes a substrate, the substrate may
include, e.g., triacetyl cellulose, cycloolefin, cycloolefin
copolymer, polynorbornene copolymer, etc., and may have an in-plane
retardation of .+-.2.5 nm or less.
In an embodiment, the touch sensor 200 may be directly transferred
to the window substrate 230 or the polarizing layer 210. In an
embodiment, the window substrate 230, the touch sensor 200 and the
polarizing layer 210 may be sequentially positioned from the
viewer's side.
The image display device may include a display panel 360 and the
window stack structure 250 disposed on the display panel 360.
The display panel 360 may include a pixel electrode 310, a pixel
defining layer 320, a display layer 330, an opposing electrode 340
and an encapsulation layer 350 disposed on a panel substrate
300.
A pixel circuit including a thin film transistor (TFT) may be
formed on the panel substrate 300, and insulation layer covering
the pixel circuit may be formed. The pixel electrode 310 may be
electrically connected to, e.g., a drain electrode of the TFT on
the insulation layer.
The pixel defining layer 320 may be formed on the insulation layer,
and the pixel electrode 310 may be exposed through the pixel
defining layer 320 such that a pixel region may be defined. The
display layer 330 may be formed on the pixel electrode 310, and the
display layer 330 may include, e.g., a liquid crystal layer or an
organic light emitting layer.
The opposing electrode 340 may be disposed on the pixel defining
layer 320 and the display layer 330. The opposing electrode 340 may
serve as, e.g., a common electrode or a cathode of the image
display device. The encapsulation layer 350 may be disposed on the
opposing electrode 340 to protect the display panel 360.
In some embodiments, the display panel 360 and the window stack
structure 250 may be combined with each other through an adhesive
layer 260. For example, a thickness of the adhesive layer 260 may
be greater than each thickness of the first adhesive layer 220 and
the second adhesive layer 225. A viscoelasticity of the adhesive
layer 260 may be about 0.2 MPa or less at a temperature ranging
from -20.degree. C. to 80.degree. C. In this case, a noise from the
display panel 360 may be blocked, and an interface stress while
being bent may be alleviated so that damages of the window stack
structure 250 may be avoided. In an embodiment, the viscoelasticity
of the adhesive layer 260 may be in a range from about 0.01 MPa to
about 0.15 MPa.
The touch sensor 200 according to exemplary embodiments as
described above may include sensing electrodes including unit cells
and optical compensation patterns aligned on the sensing
electrodes. Accordingly, degradation of an image quality from the
display panel 360 may be prevented, and improved transmittance may
be achieved.
* * * * *